Viser treff 248-267 av 928

    • Effect of Codend Design and Postponed Bleeding on Hemoglobin in Cod Fillets Caught by Bottom Trawl in the Barents Sea Demersal Fishery 

      Jensen, Tonje Kristin; Tobiassen, Torbjørn Inge; Heia, Karsten; Møllersen, Kajsa; Larsen, Roger B.; Esaiassen, Margrethe (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-03)
      Previous studies have reported that cod caught using a newly developed dual sequential codend showed significant reduction in external catch-related damage compared to cod caught by a conventional codend. In this study, it was investigated whether this new codend affects residual blood in cod fillets and/or mitigates the effect of postponed bleeding. Residual blood was assessed by measuring ...
    • Effect of codend mesh sizes on the size selectivity and exploitation pattern of cocktail shrimp (Trachypenaeus curvirostris) in shrimp trawl fishery of the South China Sea 

      Yang, Bingzhong; Herrmann, Bent (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-29)
      This study aims at improving fishery management by testing and comparing the size selectivity and exploitation pattern of diamond-mesh codends, with mesh sizes ranging from 25 to 54 mm, for cocktail shrimp (Trachypenaeus curvirostris) in the South China Sea (SCS). Beginning from 25 mm, the minimum mesh size regulated by the shrimp trawl fishery industry, we investigated how the mesh sizes of ...
    • Effect of Diet Supplemented With Rapeseed Meal or Hydrolysable Tannins on the Growth, Nutrition, and Intestinal Microbiota in Grass Carp (Ctenopharyngodon idellus) 

      Yao, Jianting; Chen, Peng; Ringø, Einar; Zhang, Gaigai; Huang, Zhongyuan; Hua, Xue-Ming (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-25)
      Grass carp (<i>Ctenopharyngodon idellus; n</i> = 320) were received four different diets for 56 days. The experimental diets were: fishmeal (FM) containing 10% fishmeal (without rapeseed meal), and rapeseed meal (RM) containing 50% rapeseed meal (without fishmeal), and two semi-purified diets either without (T0) or with 1.25% (T1) supplemental hydrolysable tannin. The approximate content of tannin ...
    • Effect of dietary components on the gut microbiota of aquatic animals. A never-ending story? 

      Ringø, Einar; Zhou, Zhigang; Vecino, Jose L. González; Wadsworth, Simon L.; Romero, Jaime; Krogdahl, Åshild; Olsen, Rolf Erik; Dimitroglou, Arkadios; Foey, Andrew David; Davies, Simon; Owen, Matthew A.G.; Lauzon, Hélène Liette; Martinsen, Lisbeth Løvmo; De Schryver, Peter; Bossier, Peter; Sperstad, Sigmund; Merrifield, Daniel Lee (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-07)
      It is well known that healthy gut microbiota is essential to promote host health and well-being. The intestinal microbiota of endothermic animals as well as fish are classified as autochthonous or indigenous, when they are able to colonize the host’s epithelial surface or are associated with the microvilli, or as allochthonous or transient (associated with digesta or are present in the lumen). ...
    • Effect of Extension Piece Design on Catch Patterns in a Mediterranean Bottom Trawl Fishery 

      Petetta, Andrea; Herrmann, Bent; Virgili, Massimo; Li Veli, Daniel; Brinkhof, Jesse; Lucchetti, Alessandro (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-18)
      The catch composition of bottom trawls is commonly refined and improved through changes in codend design. Measures like reducing the number of meshes in codend circumference or turning diamond netting by 90 degrees are well known to improve the size selectivity of fish species with rounded cross-sectional shape. Based on this we speculated whether the same measures, if applied in other parts of ...
    • Effect of gear design on catch damage on cod (Gadus morhua) in the Barents Sea demersal trawl fishery 

      Brinkhof, Jesse; Herrmann, Bent; Sistiaga, Manu; Larsen, Roger B.; Jacques, Nadine; Gjøsund, Svein Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-18)
      Damage incurred during the catch process is an indicator of the overall quality of fish and fish welfare. Because catch quality is difficult to improve once it has deteriorated, it is important to preserve quality during the catch process. Atlantic cod (<i>Gadus morhua</i>) is the most important species in the Barents Sea bottom trawl fishery. Bottom trawling is a non-benign fishing method, and it ...
    • Effect of gillnet twine thickness on capture pattern and efficiency in the Northeast-Arctic cod (Gadus morhua) fishery 

      Brinkhof, Ilmar; Herrmann, Bent; Larsen, Roger B.; Brinkhof, Jesse; Grimaldo, Eduardo; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-15)
      Gillnets are among the most common fishing gears worldwide. They are often made of thin twine, which is prone to wear and tear, limiting the lifespan of the gillnet. This increases gillnet turnover, and consequently increased risk of gear discarding, gear loss, ghost fishing and marine pollution. This might be mitigated by increasing twine thickness, and thereby breaking strength. However, the ...
    • Effect of grid section design on trawl size selectivity 

      Sistiaga, Manu; Herrmann, Bent; Brinkhof, Jesse; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-12)
      Sorting grids are introduced in trawl fisheries to improve size selectivity and reduce the variability of results obtained with sorting devices constructed of netting e.g., codends. Grids are rigid or semi-rigid structures where the bar spacing defines the sizes of fish that can pass through. However, for size selection to occur, fish need to be oriented towards the grid in specific ways, which ...
    • Effect of ground gear modification on bycatch of rays in mediterranean bottom trawl fishery 

      Fakıoğlu, Y.E.; Özbilgin, H.; Gökçe, G.; Herrmann, Bent (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-28)
      Bycatch of rays and skates in towed fishing gears represents one of the major threats to these relatively slow-growing marine species. The objective of this study was to modify ground gear in a bottom trawl fishery to increase the escape of these species during towing without associated loss of target catch. Sea trials were carried out with a research vessel in Mersin Bay, North-eastern Mediterranean. ...
    • The Effect of Gut Microbiota and Probiotics on Metabolism in Fish and Shrimp 

      Ringø, Einar; Harikrishnan, Ramasamy; Soltani, Mehdi; Ghosh, Koushik (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-03)
      The present paper presents an overview of the effects of gut microbiota and probiotics on lipid-, carbohydrate-, protein- and amino acid metabolism in fish and shrimp. In probiotic fish studies, the zebrafish (Danio rerio) model is the most frequently used, and probiotic administration reveals the effect on glucose homeostasis, anti-lipidemic effects and increasing short-chain fatty acids, and ...
    • Effect of Hook and Bait Size on Catch Efficiency in the Persian Gulf Recreational Fisheries 

      Herrmann, Bent; Eighani, Morteza; Paighambari, Seyed Yousef; Feeking, Jordan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-15)
      The effect of hook and bait sizes on the catch efficiency and size composition of Spangled Emperor <i>Lethrinus nebulosus</i>, Orange‐spotted Grouper <i>Epinephelus coioides</i>, and Narrowbarred Mackerel <i>Scomberomorus commerson</i> was investigated in the recreational and semi‐subsistence handline fishery in the Persian Gulf. Based on expectations that increasing hook and bait sizes would decrease ...
    • Effect of lifting the sweeps on bottom trawling catch efficiency on the Northeast arctic cod trawl fishery 

      Sistiaga, Manu Berrondo; Grimaldo, Eduardo; Herrmann, Bent; Larsen, Roger B.; Tatone, Ivan (Research report; Forskningsrapport, 2014)
      Fuel consumption and environmental concerns have led bottom trawlers fishing for cod (Gadus morhua) in the Barents Sea to use semi-pelagic doors. However, this change may affect fish herding and consequently the catch efficiency of the gear. In this study we compared the catch efficiency of two different setups where the sweep length with bottom contact was different. This setup also enabled us to ...
    • The effect of long-term use on the Catch efficiency of Biodegradable gillnets 

      Grimaldo, Eduardo; Herrmann, Bent; Jacques, Nadine; Kubowicz, Stephan; Cerbule, Kristine; Su, Biao; Larsen, Roger B.; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-05)
      The effect of long-term use on the catch efficiency of biodegradable gillnets was investigated during commercial fishing trials and in controlled lab aging tests. The relative catch efficiency between biodegradable and nylon gillnets was evaluated over three consecutive fishing seasons for Atlantic cod (Gadus morhua) in Norway. The biodegradable gillnets progressively lost catch efficiency over time, ...
    • Effect of mechanical properties of monofilament twines on the catch efficiency of biodegradable gillnets 

      Grimaldo, Eduardo; Herrmann, Bent; Jacques, Nadine; Su, Biao; Vollstad, Jørgen; Su, Biao (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-24)
      Gillnets made of the biodegradable resin polybutylene succinate co-adipate-co-terephthalate were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon polyamide (PA) gillnets. Both types of gillnets were made of 0.55 mm Ø monofilaments. However, since the biodegradable nets are weaker than nylon PA nets when using the same monofilament diameter, ...
    • The effect of Nordmøre grid length and angle on codend entry of bycatch fish species and shrimp catches 

      Larsen, Roger B.; Sistiaga, Manu Berrondo; Herrmann, Bent; Brinkhof, Jesse; Tatone, Ivan; Santos, Juan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-18)
      The Nordmøre grid is regarded as an efficient bycatch reducing device and is used in various shrimp trawl fisheries globally. However, in some shrimp fisheries bycatch remains a problem that seriously impacts commercial trawl activities. This study tested and compared the performance of two versions of the Nordmøre grid in the Northeast Arctic Deepwater Shrimp (Pandalus borealis) fishery; a standard ...
    • Effect of rotational harvesting on the size composition of Cape rock oysters Striostrea margaritacea on the east coast of South Africa 

      Steyn, Erika; Groeneveld, Johan C.; Santos, Antonio Jorge Fonseca Antunes (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-11)
      A commercial fishery for the Cape rock oyster Striostrea margaritacea along the north coast of KwaZulu-Natal, South Africa (western Indian Ocean), follows a 4-year rotational cycle, with each harvest year followed by 3 fallow years across four harvest zones. We analysed reported harvesting effort and catch information, and fishery-independent oyster size composition data collected over 18 years (Feb ...
    • The effect of semi-pelagic trawling on american plaice (hippoglossoides platessoides) by-catch reduction in the northeast arctic shrimp fishery 

      Sistiaga, Manu Berrondo; Grimaldo, Eduardo; Herrmann, Bent; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
      The present study reports results of a small-scale preliminary experiment to evaluate whether lifting trawl doors and sweeps from the seabed can lead to a reduction of by-catch in the Northeast Arctic shrimp trawl fishery. We carried out a catch comparison and catch ratio analysis between two gear configurations: one with trawl doors and sweeps on the seabed (traditional rigging) and the other with ...
    • The effect of temperature and dietary energy content on female maturation and egg nutritional content in Atlantic salmon 

      Maamela, Katja S.; Åsheim, Eirik Ryvoll; Debes, Paul V.; House, Andrew H.; Erkinaro, Jaakko; Liljeström, Petra; Primmer, Craig R.; Mobley, Kenyon (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-17)
      The environment experienced by a female influences reproductive traits in many species of fish. Environmental factors such as temperature and diet are not only important mediators of female maturation and reproduction but also of egg traits and offspring fitness through maternal provisioning. In this study, we use 3-year-old tank-reared Atlantic salmon from two Finnish populations to investigate the ...
    • The effect of temperature on growth performance and aerobic metabolic scope in Arctic charr, Salvelinus alpinus (L.) 

      Beuvard, Christian; Imsland, Albert; Thorarensen, Helgi (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-06)
      In recent years, Arctic char populations in Iceland have declined and the objective of this experiment was to throw further light on these changes by examining the effect of temperature (5, 9, 13, 17, and 21 °C) on the survival, growth rate, metabolism, and physiological indices of juvenile Arctic charr (initial mean body mass 4.02 ± 0.8 g). Mortality was 60% at 21 °C while at lower temperatures it ...
    • Effect of the Nordmøre grid bar spacing on size selectivity, catch efficiency and bycatch of the Barents Sea Northern shrimp fishery 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu; Brinkhof, Jesse; Cerbule, Kristine; Grimaldo Vela, Eduardo Enrique; Lomeli, Mark JM (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-27)
      The introduction of the Nordmøre grid in shrimp trawls has reduced the bycatch of non-target species. In the Norwegian Northern shrimp (Pandalus borealis) fishery, the mandatory selective gear consists of a Nordmøre grid with 19 mm bar spacing combined with a 35 mm mesh size diamond mesh codend. However, fish bycatch in shrimp trawls remains a challenge and further modifications of the gear that ...